Field of the Invention
The present invention relates to an image formation apparatus, an image formation method, and a non-transitory computer-readable recording medium storing an image formation program, capable of forming a sheet gap image with a predetermined object in a sheet gap between transfer media on which an image is formed.
Description of the Related Art
In an image formation apparatus for printing an image on a sheet with use of an electrophotographic system, there is a case where a toner image is drawn on an image bearing member such as an intermediate transfer belt in a space between sheets, to stabilize an image. As one type of a toner image, there is an image correction patch. Specifically, a patch is printed on a sheet, and the patch of an output image is detected by a color density sensor or the like and is compared with print base data. If there is a difference between them, the printing density or the like is corrected to form an image. Further, a toner image formed on an image bearing member may be read by a density sensor or the like and used for calibration of the density sensor, for example. There is also a toner consumption image for disposing old toner.
Regarding such toner images, it is possible to form patches of different purposes simultaneously in a space between sheets, and shapes of the toner images are set so as to be formed in a space between sheets.
Japanese Patent Laid-Open No. 2012-230335 proposes an image formation apparatus in which a formation region, on which toner patterns are formed, is determined to be either an end region in a main scanning direction where a print image is not formed or a space region between adjacent print images, of a region on a transfer belt. Then, a predetermined number of reference toner patterns are formed dividedly in the end region or the space region determined to be the formation region according to the size of the end region or the space region.
However, in the case of conveying sheets, there is a case where a sheet is fed in a tilted manner when it is fed from a sheet feed tray, or a sheet is caused to be tilted when it moves from the sheet feed tray to an image formation unit. In that case, a sheet is introduced to the image formation unit in a tilted state. When a sheet is conveyed in a tilted manner, a space between the rear end of a previous sheet and the front end of the subsequent sheet (hereinafter referred to as a sheet gap) is decreased. As such, when it is attempted to form a sheet gap image in a sheet gap, there is a case where a sheet gap image of a required amount cannot be formed in the sheet gap.
Further, when an image is formed in a state where a sheet is tilted, the image is drawn on the sheet in a tilted manner. In order to prevent it, there is a function of forming an image by turning the image to be written on the image bearing member according to the tilt of the sheet to thereby conform the sheet to the image data. However, when turning correction is made and the drawing region (image signal) of the image data is extended, there is a possibility that the timing of writing the toner image deviates so that the designed pattern cannot be drawn in the sheet gap, whereby the image may overlap the next image.